Using Beamsplitters

When shooting with a beam splitter, either for 3D or other purposes, you will need to make sure the focal length of the two cameras match exactly. The focal length on the barrel of a lens is oftentimes a value that has been rounded. So for example a 50mm might actually be 49.3mm or 51.2mm. The focal length on a lens barrel represents a value within a permissible tolerance range. So even two of the same model lens from the same manufacturer can vary slightly in their exact focal lengths. This will cause issues matching the images later in post. Testing will be necessary beforehand to make sure the two sets of lenses match identically.